Cu-Al-Ni-Fe alloy and sensor for measuring a physical parameter comprising a component made of such an alloy

ABSTRACT

The invention relates to a Cu—Al—Ni—Fe alloy containing from 3 to 6 wt % aluminum, from 3 to 6.5 wt % nickel, from 1 to 4.5 wt % iron, from 0.1 to 1 wt % silicon, from 0.1 to 1 wt % manganese and from 0.05 to 1 wt % tin, the other chemical elements having contents by weight of less than 1%, and the balance is copper.

[0001] The present invention relates to copper alloys.

[0002] More particularly, it relates to alloys having mechanical, thermal and electrical properties allowing them to be used in sensors that are highly stressed both thermally and mechanically, and in particular in sensors used in the field of aeronautics, for example for total air temperature measurement at an engine inlet or else for measurements on the outside of aircraft.

[0003] Many sensors in this sense are already known.

[0004] In particular, deiced total air temperature sensors of the type shown in FIG. 1 are already known.

[0005] Such a sensor 1 has in particular an air intake 11 attached to a profiled body 2 in which a duct 3 is made, allowing flow of the fluid which is to be measured and communicating with the air intake via an inertial separation region 4. This region separates, from the air, the components of relatively large mass compared with the latter (namely water, ice, sand, etc.) by centrifugation, these components being removed from the sensor through an ejection region 5 on the opposite side from the air intake. To avoid the fluid detachment phenomena in the inertial separation region 4, holes 6 are provided in the wall of the latter, on the opposite side from the ejection region 5, and communicate with the outside via a chamber 7 that extends transversely through the thickness of the profiled body 2. The pressure differential existing between the inside and the outside of the sensor allows suction of the boundary layer via the holes 6.

[0006] The air intake 11/profiled body 2/duct 3/inertial separation region 4/ejection region 5 assembly is electrically de-iced by resistance heating elements.

[0007] A component forming a measurement sensor extends along the inside of said duct 3. This component 9 is, for example, a platinum wire constituting a thermometer resistance thermally isolated from the profiled body 2.

[0008] The various wires forming a thermometer resistance or heating resistance element are connected to a connection socket 10.

[0009] The profiled body of this sensor is generally made of a beryllium-copper alloy.

[0010] This is because beryllium-copper alloys exhibit excellent mechanical, thermal and electrical properties in their various metallurgical states: a yield strength of 150 to 1000 MPa and higher, a tensile strength of 300 to 1000 MPa and higher, an elongation at break of up to 60% and a thermal conductivity of 100 W/m.K and higher.

[0011] Although the presence of beryllium improves the general properties of the material, beryllium metal dust is, however, toxic and presents a hazard to an operator during machining or assembling operations.

[0012] Out of concern for protecting operators, it is nowadays desired to be able to use alloys containing no beryllium.

[0013] Many Cu—Al—Ni—Fe alloys are already known.

[0014] The invention itself proposes a Cu—Al—Ni—Fe alloy containing from 3 to 6 wt % aluminum, from 3 to 6.5 wt % nickel, from 1 to 4.5 wt % iron, from 0.1 to 1 wt % silicon, from 0.1 to 1 wt % manganese and from 0.05 to 1 wt % tin, the other chemical elements having contents by weight of less than 1%, and the balance is copper.

[0015] Other features and advantages of the invention will also become clear from the following description, which is purely illustrative and nonrestricting, and must be read in conjunction with the single appended figure giving a total air temperature sensor.

[0016] A sensor according to one possible embodiment comprises a structure of the type illustrated in FIG. 1, in which the part constituting the profiled body 2 and the air intake 11 is made of a Cu—Al—Ni—Fe alloy having as composition:

[0017] from 3 to 6 wt % aluminum;

[0018] from 3 to 6.5 wt % nickel;

[0019] from 1 to 4.5 wt % iron;

[0020] from 0.1 to 1 wt % silicon;

[0021] from 0.1 to 1 wt % manganese; and

[0022] from 0.05 to 1 wt % tin.

[0023] The elements other than Cu, Al, Ni, Fe, Si, Mg and Sn have contents by weight of less than 1%.

[0024] The balance is made up by copper.

[0025] On as-cast batches, the mechanical properties are around 200 MPa and higher in the case of the yield strength, 300 MPa and higher in the case of the tensile strength, 10% and higher in the case of the elongation at break and 50 W/m.K and higher in the case of the thermal conductivity.

[0026] Such an alloy exhibits excellent castability properties.

[0027] However, it should be noted that it can be produced in ways other than by casting, especially by sintering.

[0028] In the case of a foundry treatment, this may be a crude foundry treatment, a foundry treatment with a heat treatment, and these may or may not be followed by forming treatments (for example machining), a foundry treatment followed immediately by forming operations (for example machining).

[0029] The parts obtained with such an alloy (whether or not obtained by casting) can be joined together perfectly using various welding techniques, various brazing techniques and various braze-welding techniques.

[0030] The alloy also exhibits excellent machinability.

[0031] It should be noted that in general the sensor includes at least one component made of an alloy of the aforementioned type.

[0032] Advantageously, this is a sensor for measuring at least one physical parameter, such as temperature, pressure, flow rate, velocity, impact.

[0033] Particularly preferably, the proposed sensor is a sensor provided with thermal deicing means for measuring at least one physical parameter on a stream of fluid.

[0034] The sensor proposed is, for example, a sensor for measuring physical parameters at the inlet of an engine or on the outside of an aircraft.

[0035] It should be noted that, in a particularly advantageous composition, the elements other than Cu, Al, Ni, Fe, Si, Mg and Sn have contents by weight of less than 0.1%.

[0036] As a more particular example, an alloy used to produce the sensor body is advantageously an alloy whose composition comprises around 4.5 wt % aluminum, around 4 wt % nickel, around 2 wt % iron, around 0.5 wt % silicon, around 0.3 wt % manganese and around 0.1 wt % tin.

[0037] Such an alloy has a yield strength of 230 MPa, a tensile strength of 400 MPa, an elongation at break of 18% and a thermal conductivity of 70 W/m.K 

1. A Cu—Al—Ni—Fe alloy containing from 3 to 6 wt % aluminum, from 3 to 6.5 wt % nickel, from 1 to 4.5 wt % iron, from 0.1 to 1 wt % silicon, from 0.1 to 1 wt % manganese and from 0.05 to 1 wt % tin, the other chemical elements having contents by weight of less than 1%, and the balance is copper.
 2. The alloy as claimed in claim 1, wherein the other chemical elements have contents by weight of the order of or less than 0.1%.
 3. The alloy as claimed in claim 2, containing around 4.5 wt % aluminum, around 4 wt % nickel, around 2 wt % iron, around 0.5 wt % silicon, around 0.3 wt % manganese and around 0.1 wt % tin.
 4. A sensor for measuring at least one physical parameter, such as temperature, pressure, flow rate, velocity, impact, which includes at least one component made of an alloy as claimed in one of the preceding claims.
 5. A sensor provided with thermal deicing means for measuring at least one physical parameter on a stream of fluid, which includes at least one component made of an alloy as claimed in one of claims 1 to
 3. 6. A sensor for measuring physical parameters at the inlet of an engine or on the outside of an aircraft, which includes at least one component made of an alloy as claimed in one of claims 1 to
 3. 7. A process for producing a component made of an alloy as claimed in one of claims 1 to 3, wherein a foundry treatment is carried out.
 8. The process as claimed in claim 7, wherein the foundry treatment is a crude foundry treatment.
 9. The process as claimed in claim 7, wherein the foundry treatment is a foundry treatment with a heat treatment.
 10. The process as claimed in claim 9, wherein the heat treatments are followed by forming treatments.
 11. The process as claimed in claim 7, wherein the foundry treatment is immediately followed by forming operations.
 12. A process for producing a component made of an alloy as claimed in one of claims 1 to 3, wherein a sintering treatment is carried out. 